Method for making motor rotors



April 8, 194-1. w. 1.. HANSEN EIAL METHOD FOR MAKING MOTOR ROTORS Original Filed July 3, 1939 WILL/AM L- HANSEN IRA N HURST M 132% ATTOFF/VE Y3 Patented Apr. 8, 1941:

METHOD FOR MAKING MOTOR ROTORS 1 William L. Hansen and Ira N. Hurst, Princeton,

InlL, animal: to Hansen Manufacturing Company, Inc., Princeton, 11141., a corporation of Indiana Original application July 3, 1939, Serial No.

1940,- Serial No. 329,696

- Claims. (Cl. 172-120) This invention relates to electrical synchronous motors, and in particular, to rotors for such mo-,

tors and processes of making such rotors.

One object of this invention is to provide a rotor for an electrical synchronous motor including a substantially cylindrical band of magnetic.

material having a plurality of incisions for providing pole pieces.

Another object is to provide such s. rotor wherein, the incisions constitute substantially arcuate slots formed in the cylindrical band.

Anotherobject is to provide a rotor comprising a shaft with a support thereon having a periph eral flange, and a cylindrical band of magnetic material disposed within said flange and having a plurality of incisions therein forminig pole pieces. 1

This application is a division of our application,

SerialyNo. 282,719, filed July 3, 1939.

In the drawing:

} Figure 1 is a perspective view of a preferred embodiment of the rotor of this invention.

. Figure. 2 is a front elevation of a motor em ploying the rotor of this invention, the rotor being partly broken away to disclosethe structure behind it.

Figure 3 is a partially sectional side elevation along the line 33inFlgure 2. i

Figure 4 is a perspective view of a strip of magnetic material from which the rotor band may be made. Y

Figure 5 is a. perspective view showing the strip I of Figure 4 provided with incisions to form upstanding tabs.

Figure 6 is a section along the line 2-3 in" Figure 5.

therein Divided and this application April 15,

shows the rotor of this invention as consisting of a shaftiii-having a hub ii with a web l2 extending outwardly therefrom, and having a peripheral flange i3. Mounted within the flange i3 is s. rotor bandll of substantially cylindrical form. This rotor band I4 is preferably of magnetic steel and may be formed either in a single piece or in the form of a strip which is sprung into the space within the flange l3, as hereinafter explained. The rotor band It is provided with circumferentially spaced incisions 15, which serve to interrupt the magnetic path and in this manner to provide pole pieces around the rotor band it. v

The rotor of Figure 1, generally designated i6, is shown in position upon a motor in Figures 2 and 3. This motor may be of any suitable, type, the type shown being described and claimed in our copending application, Ser. No. 282,718, filed July 3,1939. This motor consists of a magnetic core I] having reduced diameter portions l8 and is, upon which are mounted outer and inner pole members 20 and 2|, respectively.

The outer pole member 20 is provided with axially extending pole pieces 22 and 23, which are alternately encircled by an undulating shading member 24 of non-magnetic metal, such as copper. The shading member24 passes over the outer surfaces of the pole pieces 22 and their undulating portions 25 extend substantially around three sides of each pole piece 23, leaving the outer surface thereof exposed. In this manner the outer pole'pieces 23 are shaded, whereas theouter pole pieces 22 are left unshaded,

The inner pole member 2| is provided with radiating pole pieces-26 and 21, the tips of which into alignment with the. remainder of the strip.

Figure 8 is a section along the line H in Fig-- ure 7. I

Figure 9 1s an elevation of a1 ring or 1 magnetic material from which the rotor may be made-by a modified procedure.

Figure 10 isan enlarged view of a portion of therein,and a tab struck upwardly therefrom.

i in: over one surface only of .each pole piece 26.

the ring shown'in Figure 9 with an incision made Figure 11 is a view similar to Figures 9 and 10,

but in a later stage or manufacture with the tabs bent backward into alignment with the remainder of the ring.

Figure 12 is a view of the finished rotor band with a portion-of the ring of Figure 11 bent intocylindrical form.

Referring to the drawinaindetail,

extend outward into close proximity to the tips of the outer pole pieces 22 and 23. The inner pole pieces-21' are shaded by a shading ring 28 having undulating portions 28 passing around three sides-of each'inner pole piece 21, but pass- In this manner the inner pole pieces 21- are shaded. whereas the inner pole pieces 28 are left unshaded. The shadingringn is likewise of nonmagnetic metal, such as copper.

In order to energize the field structurethus described the core I1 is encircled by a grooved 'insulating member 20 having a field energizing winding therein; 1 The core I! is provided with a bore 3| with plugs-"and SI havingcoaxial bores I4 and fl'for'rotatably supportingthe ro-- tor shaft ii. The rotor band It is then disn 1 pole members 22, 22,- 2| and 21'. The incisionsadiacent the-tips or the outer and inner punching process tabs l5 are struck up from the surface of the strip M, as shown in Figures 5 and 6. Subsequently, however, these tabs 55* are pushed or bent back'into alignment with the remainder of the strip ht, as shown in Figures 7 and 8. The strip may then be sprung into cylindrical shape and inserted within the flange it, where it is held in place by its natural resilience.

In the second process of manufacture a ring tions' back into alignment with the remainder of the strip.

36 of magnetic steel is selected and provided with,

incisions i5, spaced circumferentially therearound by a punching process as shown in Figure 10. During the punching process tabs 95 are raised above the adjacent surface of the ring 36, as shown in Figure 10. Subsequently, however, these tabs 55* are bent or pushed back into alignment with the remainder of the ring, as shown in Figure 11. The ring is then subjected to the action of mating dies so that the peripheral portion of the ring 36 is drawn into an axial cylindrical flange 3i. By this means the rotor band may be made in a single piece.

It will be understood that we desire to comprehend within our invention such modifications as come within the scope 'of the claims and the invention.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a process of making a rotor, forming 3. In a process of making a rotor, forming spaced transverse incisions in a ring of magnetic material while striking up portions of the strip adjacent said incisions, and bending the struck-up portions back into alignment with the remainder of the strip.

4. In a process of making a rotor, forming spaced transverse incisions in a ring of magnetic material while striking up portions of the strip adjacent said incisions, bending the struck-up portions back into alignment with the remainder of the strip, and bending the edge portion of said ring into a substantially cylindrical shape.

5. In a process 0f making a rotor, forming spaced transverse incisions in a ring of magnetic material while striking up portions of the strip adjacent. said incisions, bending .the struck-up portions back into alignment with the remainder of the strip, and bending the edge portion oi said ring into a substantially cylindrical shape while leaving the opposite edge portion of the ring to form a flange.

WILLIAM L. HANSEN.

IRA N. HURST. 

